Methylene, difluoro-

Formula: CF₂
Molecular weight: 50.0075
IUPAC Standard InChI: InChI=1S/CF2/c2-1-3
IUPAC Standard InChIKey: LTVOKYUPTHZZQH-UHFFFAOYSA-N
CAS Registry Number: 2154-59-8
Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript.
Other names: Calcium difluoride; Difluoromethylene
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Gas phase thermochemistry data

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Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_gas	-43.499	kcal/mol	Review	Chase, 1998	Data last reviewed in June, 1970
Δ_fH°_gas	-41.1 ± 2.0	kcal/mol	Eqk	Ehlert, 1969	ALS
Quantity	Value	Units	Method	Reference	Comment
S°_{gas,1 bar}	57.560	cal/mol*K	Review	Chase, 1998	Data last reviewed in June, 1970

Gas Phase Heat Capacity (Shomate Equation)

C_p° = A + B*t + C*t² + D*t³ + E/t²
H° − H°_298.15= A*t + B*t²/2 + C*t³/3 + D*t⁴/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t²/2 + D*t³/3 − E/(2*t²) + G
C_p = heat capacity (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.

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View table.

Temperature (K)	298. to 600.	600. to 6000.
A	2.109410	14.18440
B	29.96300	-0.553818
C	-30.94981	0.212839
D	12.02940	-0.013355
E	0.062082	-0.828763
F	-45.00280	-50.09931
G	52.79830	71.28511
H	-43.50000	-43.50000
Reference	Chase, 1998	Chase, 1998
Comment	Data last reviewed in June, 1970	Data last reviewed in June, 1970

Reaction thermochemistry data

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Data compiled by: John E. Bartmess

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

(CF₃^- • 4294967295 Methylene, difluoro- ) + = CF₃^-

By formula: (CF₃^- • 4294967295CF₂) + CF₂ = CF₃^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	49.8 ± 2.4	kcal/mol	N/A	Deyerl, Alconcel, et al., 2001	gas phase; Adiabatic EA, from vibrational structure of spectrum
Δ_rH°	50.9 ± 2.9	kcal/mol	N/A	Bartmess, Scott, et al., 1979	gas phase; Paulino and Squires, 1991 suggests that this acidity may be too weak by ca. 5 kcal/mol. However, G2 calcn(JEB) give ΔHacid=379.9, ΔGacid=372.0; value altered from reference due to change in acidity scale
Δ_rH°	55.9 ± 2.7	kcal/mol	CIDT	Paulino and Squires, 1991	gas phase; Neutral heat is based on a fluoroform acidity that may be too weak by up to 5 kcal/mol

(CAS Reg. No. 53959-80-1 • 4294967295 Methylene, difluoro- ) + = CAS Reg. No. 53959-80-1

By formula: (CAS Reg. No. 53959-80-1 • 4294967295CF₂) + CF₂ = CAS Reg. No. 53959-80-1

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	<8.00	kcal/mol	CIDT	Paulino and Squires, 1991, 2	gas phase; Probably CF2..Cl-, non-covalent.

Gas phase ion energetics data

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Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
LL - Sharon G. Lias and Joel F. Liebman
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess

View reactions leading to CF₂⁺ (ion structure unspecified)

Quantity	Value	Units	Method	Reference	Comment
IE (evaluated)	11.44 ± 0.03	eV	N/A	N/A	L
Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	183.	kcal/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	175.1	kcal/mol	N/A	Hunter and Lias, 1998	HL

Electron affinity determinations

EA (eV)	Method	Reference	Comment
0.180 ± 0.020	LPES	Schwartz, Davico, et al., 1999	Neutral carbene triplet 54±3 kcal/mol above singlet; B
0.1790 ± 0.0050	LPES	Murray, Leopold, et al., 1988	Singlet-triplet splitting in neutral > 50 kcal/mol; B
0.07 ± 0.15	D-EA	Born, Ingemann, et al., 1994	B
<1.30 ± 0.80	EIAE	Harland and Thynne, 1972	From C2F4. G3MP2B3 calculations indicate an EA of ca. 0.4 eV.; B
>0.20047	EIAE	Thynne and MacNeil, 1970	From C2F4. G3MP2B3 calculations indicate an EA of ca. 0.4 eV.; B
2.64955	SI	Page and Goode, 1969	The Magnetron method, lacking mass analysis, is not considered reliable.; B

Ionization energy determinations

IE (eV)	Method	Reference	Comment
11.445 ± 0.025	PI	Buckley, Johnson, et al., 1995	LL
15.2	EI	Goto, Nakamura, et al., 1994	LL
11.5 ± 0.4	EI	Tarnovsky and Becker, 1993	LL
11.4 ± 0.3	EI	Hildenbrand, 1975	LLK
11.5 ± 0.1	EI	Hildenbrand, 1975	LLK
11.42 ± 0.01	PE	Dyke, Golob, et al., 1974	LLK
9.74	DER	Reinke, Kraessig, et al., 1973	LLK
11.54 ± 0.10	EI	Hildenbrand, 1973	LLK
11.7 ± 0.2	EI	Ehlert, 1969, 2	RDSH
11.8 ± 0.3	EI	Zmbov, Uy, et al., 1968	RDSH
11.9 ± 0.1	EI	Pottie, 1965	RDSH
11.7 ± 0.1	EI	Fisher, Homer, et al., 1965	RDSH

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
CF⁺	18.5	F	EI	Goto, Nakamura, et al., 1994	LL
CF⁺	14.6 ± 0.4	F	EI	Tarnovsky, Kurunczi, et al., 1993	LL
F⁺	31.4 ± 1.0	CF⁺	EI	Tarnovsky, Kurunczi, et al., 1993	LL

Ion clustering data

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Data compiled by: John E. Bartmess

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

(CF₃^- • 4294967295 Methylene, difluoro- ) + = CF₃^-

By formula: (CF₃^- • 4294967295CF₂) + CF₂ = CF₃^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	49.8 ± 2.4	kcal/mol	N/A	Deyerl, Alconcel, et al., 2001	gas phase; Adiabatic EA, from vibrational structure of spectrum
Δ_rH°	50.9 ± 2.9	kcal/mol	N/A	Bartmess, Scott, et al., 1979	gas phase; Paulino and Squires, 1991 suggests that this acidity may be too weak by ca. 5 kcal/mol. However, G2 calcn(JEB) give ΔHacid=379.9, ΔGacid=372.0; value altered from reference due to change in acidity scale
Δ_rH°	55.9 ± 2.7	kcal/mol	CIDT	Paulino and Squires, 1991	gas phase; Neutral heat is based on a fluoroform acidity that may be too weak by up to 5 kcal/mol

Vibrational and/or electronic energy levels

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Data compiled by: Marilyn E. Jacox

State: B ?

Energy (cm^-1)		Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o = 72740	T	gas	B-X	131	138	Mathews, 1967

State: A

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o = 37216	gas	A-X	220	380	Venkateswarlu, 1950
					Laird, Andrews, et al., 1950
					Mann and Thrush, 1960
					Thrush and Zwolenik, 1963
					Mathews, 1967
					King, Schenck, et al., 1979
					Cameron, Kable, et al., 1995
					Wang, Chen, et al., 1998
T_o = 37219 ± 2	Ne				Bondybey, 1976
T_o = 36878 ± 2	Ar	A-X	210	346	Bass and Mann, 1962
					Milligan, Mann, et al., 1964
					Smith, Jacox, et al., 1976
					Bondybey, 1976
T_o = 37054 ± 2	N₂				Bondybey, 1976

Vib. sym.	No.	Approximate type of mode	cm^-1	Med.	Method	References


a₁	1	Sym. stretch	1012.1 ± 0.5	gas	LF	Cameron, Kable, et al., 1995 Wang, Chen, et al., 1998
	2	Bend	496.7 ± 0.5	gas	UV LF	Venkateswarlu, 1950 Laird, Andrews, et al., 1950 Mann and Thrush, 1960 Thrush and Zwolenik, 1963 Mathews, 1967 Wang, Chen, et al., 1998
	2	Bend	496 ± 2	Ne	LF	Bondybey, 1976
	2	Bend	496 ± 2	Ar	AB	Bass and Mann, 1962 Milligan, Mann, et al., 1964 Smith, Jacox, et al., 1976
	2	Bend	496 ± 2	Ar	LF	Bondybey, 1976
	2	Bend	496 ± 2	N₂	LF	Bondybey, 1976
b₂	3	Asym. stretch	1180.2 ± 0.5	gas	LF	Cameron, Kable, et al., 1995 Wang, Chen, et al., 1998

State: a

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o = 19828	gas	a-X	430	800	Koda, 1978
					Koda, 1979
					Toby and Toby, 1980
					Koda, 1982
					Zhou, Zhan, et al., 1985
					Murray, Leopold, et al., 1988
					Schwartz, Davico, et al., 1999, 2

Vib. sym.	No.	Approximate type of mode	cm^-1	Med.	Method	References


a₁	1	Sym. stretch	1020 ± 30	gas	PE	Schwartz, Davico, et al., 1999, 2
	2	Bend	517	gas	CL	Koda, 1978 Toby and Toby, 1980 Koda, 1982 Zhou, Zhan, et al., 1985 Schwartz, Davico, et al., 1999, 2

State: B

No.	Approximate type of mode	cm^-1	Med.	Method	References


2	Bend	625	gas	AB	Mathews, 1967

State: X

Vib. sym.	No.	Approximate type of mode	cm^-1		Med.	Method	References


a₁	1	Sym. stretch	1225.08		gas	DL IR	Davies, Lewis-Bevan, et al., 1981 Orlando, Reid, et al., 1987 Burkholder, Howard, et al., 1988 Wormhoudt, McCurdy, et al., 1989
	1	Sym. stretch	1225.08		gas	PE	Murray, Leopold, et al., 1988
	1	Sym. stretch	1221.9		Ne	IR LF	Snelson, 1970 Bondybey, 1976 Forney, Jacox, et al., 1994
	1	Sym. stretch	1222	vs	Ar	IR LF	Milligan, Mann, et al., 1964 Milligan and Jacox, 1968 Bondybey, 1976
	2	Bend	666.25		gas	UV DL	Venkateswarlu, 1950 Mathews, 1967 Murray, Leopold, et al., 1988 Qian and Davies, 1995
	2	Bend	668	w	Ar	IR LF	Milligan, Mann, et al., 1964 Milligan and Jacox, 1968 Bondybey, 1976
b₂	3	Asym.stretch	1114.44		gas	IR DL	Herr and Pimentel, 1965 Lefohn and Pimentel, 1971 Davies, Hamilton, et al., 1983 Burkholder, Howard, et al., 1988 Suto and Steinfeld, 1990
	3	Asym.stretch	1105.8		Ne	IR	Snelson, 1970 Forney, Jacox, et al., 1994
	3	Asym. stretch	1102	vs	Ar	IR	Milligan, Mann, et al., 1964 Milligan and Jacox, 1968

Additional references: Jacox, 1994, page 97; Jacox, 1998, page 196; Jacox, 2003, page 137; Powell and Lide, 1966; Mathews, 1966; Basco and Hathorn, 1971; Kirchhoff, Lide, et al., 1973; Akins, King, et al., 1979; Duignan, Hudgens, et al., 1982; Charo and De Lucia, 1982; Hack and Langel, 1983; Hack and Wilms, 1986; Booth and Hancock, 1988; Ibuki, Hiraya, et al., 1989; Hermann, 1990; Creasey, Lambert, et al., 1990; Cameron and Kable, 1998; Hansen, Mader, et al., 2000

Notes

Weak

Very strong

Tentative assignment or approximate value

Energy separation between the v = 0 levels of the excited and electronic ground states.

References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Vibrational and/or electronic energy levels, NIST Free Links, Notes

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Ehlert, 1969
Ehlert, T.C., Bonding in C₁ and C₂ fluroides, J. Phys. Chem., 1969, 73, 949-953. [all data]

Deyerl, Alconcel, et al., 2001
Deyerl, H.J.; Alconcel, L.S.; Continetti, R.E., Photodetachment imaging studies of the electron affinity of CF3, J. Phys. Chem. A, 2001, 105, 3, 552-557, https://doi.org/10.1021/jp003137k . [all data]

Bartmess, Scott, et al., 1979
Bartmess, J.E.; Scott, J.A.; McIver, R.T., Jr., The gas phase acidity scale from methanol to phenol, J. Am. Chem. Soc., 1979, 101, 6047. [all data]

Paulino and Squires, 1991
Paulino, J.A.; Squires, R.R., Carbene Thermochemistry from Collision-Induced Dissociation Threshold Energy Measurements - The Heats of Formation of X1A1 CF2 and X1A1 CCl2, J. Am. Chem. Soc., 1991, 113, 15, 5573, https://doi.org/10.1021/ja00015a009 . [all data]

Paulino and Squires, 1991, 2
Paulino, J.A.; Squires, R.R., Carbene Anion Complexes - Unusual Structural and Thermochemical Features of alpha-Halocarbanions in the Gas Phase, J. Am. Chem. Soc., 1991, 113, 5, 1845, https://doi.org/10.1021/ja00005a067 . [all data]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Schwartz, Davico, et al., 1999
Schwartz, R.L.; Davico, G.E.; Ramond, T.M.; Lineberger, W.C., Singlet-triplet splittings in CX2 (X = F, Cl, Br, I) dihalocarbenes via negative ion photoelectron spectroscopy, J. Phys. Chem. A, 1999, 103, 41, 8213-8221, https://doi.org/10.1021/jp992214c . [all data]

Murray, Leopold, et al., 1988
Murray, K.K.; Leopold, D.G.; Miller, T.M.; Lineberger, W.C., Photoelectron Spectroscopy of the Halocarbene Anions HCF^-, HCCl^-, HCBr^-, HCI^-, CF₂^-, and CCl₂^-, J. Chem. Phys., 1988, 89, 9, 5442, https://doi.org/10.1063/1.455596 . [all data]

Born, Ingemann, et al., 1994
Born, M.; Ingemann, S.; Nibbering, N.M.M., Heats of formation of mono-halogen-substituted carbenes. Stability and reactivity of CHX(center dot-) (X=F, Cl, Pr, and I) radical anions, J. Am. Chem. Soc., 1994, 116, 16, 7210, https://doi.org/10.1021/ja00095a025 . [all data]

Harland and Thynne, 1972
Harland, P.W.; Thynne, J.C.J., Ionisation of perfluorocyclobutane by electron impact, Int. J. Mass Spectrom. Ion Phys., 1972, 10, 11. [all data]

Thynne and MacNeil, 1970
Thynne, J.C.J.; MacNeil, K.A.G., Ionisation of Tetrafluoroethylene by Electron Impact, Int. J. Mass Spectrom. Ion Phys., 1970, 5, 3-4, 329, https://doi.org/10.1016/0020-7381(70)80026-2 . [all data]

Page and Goode, 1969
Page, F.M.; Goode, G.C., Negative Ions and the Magnetron., Wiley, NY, 1969. [all data]

Buckley, Johnson, et al., 1995
Buckley, T.J.; Johnson, R.D.; Huie, R.E.; Zhang, Z.; Kuo, S.C.; Klemm, R.B., Ionization energies, appearance energies, and thermochemistry of CF₂O and FCO, J. Phys. Chem., 1995, 99, 4879. [all data]

Goto, Nakamura, et al., 1994
Goto, M.; Nakamura, K.; Toyoda, H.; Sugai, H., Cross section measurements for electron-impact dissociation of CHF₃ into neutral and ionic fragments, Jpn. J. Appl. Phys. Part 1, 1994, 33, 3602. [all data]

Tarnovsky and Becker, 1993
Tarnovsky, V.; Becker, K., Absolute partial cross sections for the parent ionization of the CF_x (x = 1-3) free radicals by electron impact, J. Chem. Phys., 1993, 98, 7868. [all data]

Hildenbrand, 1975
Hildenbrand, D.L., Vertical ionization potential of the CF₂ radical, Chem. Phys. Lett., 1975, 32, 30. [all data]

Dyke, Golob, et al., 1974
Dyke, J.M.; Golob, L.; Jonathan, N.; Morris, A.; Okuda, M., Vacuum ultraviolet photoelectron spectroscopy of transient species. Part 4. Difluoromethylene and ozone, J. Chem. Soc. Faraday Trans. 2, 1974, 70, 1828. [all data]

Reinke, Kraessig, et al., 1973
Reinke, D.; Kraessig, R.; Baumgartel, H., Photoreactions of small organic molecules, Z. Naturforsch. A:, 1973, 28, 1021. [all data]

Hildenbrand, 1973
Hildenbrand, D.L., Mass spectrometric studies of some gaseous sulfur fluorides, J. Phys. Chem., 1973, 77, 897. [all data]

Ehlert, 1969, 2
Ehlert, T.C., Bonding in C₁ and C₂ fluorides, J. Phys. Chem., 1969, 73, 949. [all data]

Zmbov, Uy, et al., 1968
Zmbov, K.F.; Uy, M.; Margrave, J.L., Mass spectrometric study of the high-temperature equilibrium C₂F₄ = 2CF₂ and the heat of formation of the CF₂ radical, J. Am. Chem. Soc., 1968, 90, 5090. [all data]

Pottie, 1965
Pottie, R.F., Ionization potential and heat of formation of the difluoromethylene radical, J. Chem. Phys., 1965, 42, 2607. [all data]

Fisher, Homer, et al., 1965
Fisher, I.P.; Homer, J.B.; Lossing, F.P., Free radicals by mass spectrometry. XXXIII. Ionization potentials of CF₂, CF₃CF₂, CF₃CH₂, n-C₃F₇, and i-C₃F₇ radicals, J. Am. Chem. Soc., 1965, 87, 957. [all data]

Tarnovsky, Kurunczi, et al., 1993
Tarnovsky, V.; Kurunczi, P.; Rogozhnikov, D.; Becker, K., Absolute cross sections for the dissociative electron impact ionization of the CFx (x=1-3) free radicals, Int. J. Mass Spectrom. Ion Processes, 1993, 128, 181. [all data]

Mathews, 1967
Mathews, C.W., THE ABSORPTION SPECTRUM OF CF, Can. J. Phys., 1967, 45, 7, 2355, https://doi.org/10.1139/p67-188 . [all data]

Venkateswarlu, 1950
Venkateswarlu, P., On the Emission Bands of CF2, Phys. Rev., 1950, 77, 5, 676, https://doi.org/10.1103/PhysRev.77.676 . [all data]

Laird, Andrews, et al., 1950
Laird, R.K.; Andrews, E.B.; Barrow, R.F., The absorption spectrum of CF2, Trans. Faraday Soc., 1950, 46, 803, https://doi.org/10.1039/tf9504600803 . [all data]

Mann and Thrush, 1960
Mann, D.E.; Thrush, B.A., On the Absorption Spectrum of CF2 and Its Vibrational Analysis, J. Chem. Phys., 1960, 33, 6, 1732, https://doi.org/10.1063/1.1731493 . [all data]

Thrush and Zwolenik, 1963
Thrush, B.A.; Zwolenik, J.J., Predissociation in the absorption spectra of CF and CF2, Trans. Faraday Soc., 1963, 59, 582, https://doi.org/10.1039/tf9635900582 . [all data]

King, Schenck, et al., 1979
King, D.S.; Schenck, P.K.; Stephenson, J.C., Spectroscopy and photophysics of the CF2 system, J. Mol. Spectrosc., 1979, 78, 1, 1, https://doi.org/10.1016/0022-2852(79)90031-6 . [all data]

Cameron, Kable, et al., 1995
Cameron, M.R.; Kable, S.H.; Bacskay, G.B., The electronic spectroscopy of jet-cooled difluorocarbene (CF2): The missing A-state stretching frequencies, J. Chem. Phys., 1995, 103, 11, 4476, https://doi.org/10.1063/1.470728 . [all data]

Wang, Chen, et al., 1998
Wang, C.; Chen, C.; Dai, J.; Ma, X., Laser-induced fluorescence studies of jet-cooled CF2: determination of Ã-state stretching frequencies, Chem. Phys. Lett., 1998, 288, 2-4, 473, https://doi.org/10.1016/S0009-2614(98)00275-9 . [all data]

Bondybey, 1976
Bondybey, V.E., Vibrationally unrelaxed fluorescence in matrix isolated CF2, J. Mol. Spectrosc., 1976, 63, 2, 164, https://doi.org/10.1016/0022-2852(76)90002-3 . [all data]

Bass and Mann, 1962
Bass, A.M.; Mann, D.E., Absorption Spectrum of CF2 Trapped in an Argon Matrix, J. Chem. Phys., 1962, 36, 12, 3501, https://doi.org/10.1063/1.1732492 . [all data]

Milligan, Mann, et al., 1964
Milligan, D.E.; Mann, D.E.; Jacox, M.E.; Mitsch, R.A., Infrared Spectrum of CF2, J. Chem. Phys., 1964, 41, 5, 1199, https://doi.org/10.1063/1.1726051 . [all data]

Smith, Jacox, et al., 1976
Smith, C.E.; Jacox, M.E.; Milligan, D.E., The absorption and fluorescence spectra of matrix-isolated CF2, J. Mol. Spectrosc., 1976, 60, 1-3, 381, https://doi.org/10.1016/0022-2852(76)90141-7 . [all data]

Koda, 1978
Koda, S., Emission and energy transfer of triplet difluoromethylene produced in the reaction of oxygen atoms with tetrafluoroethylene, Chem. Phys. Lett., 1978, 55, 2, 353, https://doi.org/10.1016/0009-2614(78)87037-7 . [all data]

Koda, 1979
Koda, S., Mechanism of oxygen (3P) atom reaction with tetrafluoroethylene and quenching processes of the emission of difluoromethylene (3B1), J. Phys. Chem., 1979, 83, 16, 2065, https://doi.org/10.1021/j100479a004 . [all data]

Toby and Toby, 1980
Toby, S.; Toby, F.S., Singlet and triplet emission from difluoromethylene in the reaction of ozone with tetrafluorethene, J. Phys. Chem., 1980, 84, 2, 206, https://doi.org/10.1021/j100439a016 . [all data]

Koda, 1982
Koda, S., Initial vibrational distribution and relaxation of 3CF2 produced in the reaction of oxygen atoms with tetrafluoroethylene, Chem. Phys., 1982, 66, 3, 383, https://doi.org/10.1016/0301-0104(82)88038-5 . [all data]

Zhou, Zhan, et al., 1985
Zhou, S.; Zhan, M.; Qiu, Y.; Liu, S.; Shi, J.; Li, F.; Yao, J., Chemiluminescence of CF2(3B1) produced by the reaction O(3P) + C2F4, Chem. Phys. Lett., 1985, 121, 4-5, 395, https://doi.org/10.1016/0009-2614(85)87201-8 . [all data]

Schwartz, Davico, et al., 1999, 2
Schwartz, R.L.; Davico, G.E.; Ramond, T.M.; Lineberger, W.C., Singlet-Triplet Splittings in CX, J. Phys. Chem. A, 1999, 103, 41, 8213, https://doi.org/10.1021/jp992214c . [all data]

Davies, Lewis-Bevan, et al., 1981
Davies, P.B.; Lewis-Bevan, W.; Russell, D.K., Infrared diode laser spectrum of the ν1 band of CF2 (X 1A1), J. Chem. Phys., 1981, 75, 12, 5602, https://doi.org/10.1063/1.441998 . [all data]

Orlando, Reid, et al., 1987
Orlando, J.J.; Reid, J.; Smith, D.R., Time-resolved tunable diode laser detection of products of CF2HCl IRMPD: A linestrength measurement for CF2, Chem. Phys. Lett., 1987, 141, 5, 423, https://doi.org/10.1016/0009-2614(87)85053-4 . [all data]

Burkholder, Howard, et al., 1988
Burkholder, J.B.; Howard, C.J.; Hamilton, P.A., Fourier transform spectroscopy of the ν1 and ν3 fundamental bands of CF2, J. Mol. Spectrosc., 1988, 127, 2, 362, https://doi.org/10.1016/0022-2852(88)90126-9 . [all data]

Wormhoudt, McCurdy, et al., 1989
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Notes

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Symbols used in this document:

AE	Appearance energy
EA	Electron affinity
IE (evaluated)	Recommended ionization energy
S°_{gas,1 bar}	Entropy of gas at standard conditions (1 bar)
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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